It is well known in the art of bullets for rifles that a gas check may be placed on the rear end of a bullet to protect the bullet from the adverse effects of the explosion that propels the bullet. One form of gas check is a cylindrical sleeve over a limited length of the bullet at its rear end. Another form of gas check, actually on the market, is known as the Hornady gas check. It is essentially a shallow metal cup wherein the free end of the side wall of the cup is enlarged. After the aforesaid Hornady gas check is applied to the rear end of the bullet there is a sizing step which forces the free end of the cup into the surface of the bullet; that is there is a wedge-shaped projection at the free end of the shallow cup that has actually pierced the surface of the bullet.
Patents showing bullets with some form of gas check include Boekel U.S. Pat. No. 36,449, of Sep. 16, 1862; Wray U.S. Pat. No. 996,820 of Jul. 4, 1911; Whipple U.S. Pat. No. 2,345,863 of Apr. 4, 1944; Frost U.S. Pat. No. 2,898,666 of Aug. 11, 1959; Hettes et al. U.S. Pat. No. 3,233,304 of Feb. 8, 1966; Deveney U.S. Pat. No. 4,129,024 of Dec. 12, 1978; and Ramage U.S. Pat. No. 4,492,010 of Jan. 8, 1985. Of these patents Hettes and Ramage, along with Bond and Novak U.S. Pat. Nos. 1,718,107 and 2,825,259, respectively, disclose lever operated swaging or pressing mechanisms for resizing, reloading or applying a gas check to a bullet.
Other patents teach forming thimbles, caps or cartridge cases from a cylindrical disc. These patents include Frank U.S. Pat. No. 841,954 of Jan. 22, 1907; W. T. Lyon U.S. Pat. No. 1,203,124 of Oct. 31, 1916; Butler U.S. Pat. No. 2,350,491 of Jun. 6, 1944; and G. Lyon 2,360,354 of Oct. 17, 1944.